In recent years the interior and exterior design of buildings and structures, as well as the furnishings therefor, have employed increasing quantities of decorative glass. For example, it is now commonplace for glass sheets to be used in various types of doors such as shower doors, storm doors, patio doors, entry doors, bi-fold doors, and in decorative windows, mirrors, and other furniture and architectural applications. As the scope of architectural and design tastes expand, the industry has become receptive to glass sheet products which have unique visual effects.
One such visual effect is achieved by the use of a ground groove in the surface of such glass products. The groove is formed by grinding into the surface of an annealed glass sheeting, however, the glass sheets may subsequently be bent, or curved, or further processed (such as by tempering). A unique and attractive method for achieving a remarkable visual effect is disclosed in U.S. Pat. No. 5,409,416 to Eichhorn et al. In that patent is described a decorative glass sheet having a plurality of immediately adjacent parallel grooves and a method for forming the same. Such grooves have steeper walls, thereby achieving more extreme refraction and/or reflection results, more distortion, and therefore a more striking visual difference between the ribbed or grooved section and the other surface of the glass sheet.
Another related use for glass sheets is in insulated glass units (commonly referred to as "IGUs") as used in windows or patio doors for residential and commercial buildings. IGUs typically include a frame in which two sheets of glass or plexiglass are mounted in a parallel arrangement, supported by the frame which engages their respective peripheral edges. The panes define a gap therebetween and, in combination with the frame which spans the gap about the edges, form an enclosed airspace therein. The airspace serves as an insulator.
One problem experienced with conventional IGUs involves the simulation of traditional paned windows. Traditional paned window generally consist of a plurality of panes separated by a grid of muntins. It is known to provide a grid of aluminum or like material secured to the inner surface (i.e., facing the gap) or outer surface of the inside glass panel (i.e., the panel adjacent the interior of the dwelling). These grids, being formed from materials having greater heat transfer properties than the air or vacuum in the airspace, compromise the insulating efficiency of the IGU. Additional disadvantages of these types of grid include their tendency to become loose during shipment resulting in unsatisfactory rattles upon installation. Additionally, the grids can be difficult to install correctly and, as a result, often become crooked during use.
Thus, there exists a need for a decorative glass sheet having a unique decorative visual effect. There exists a need for such a glass sheet which may be incorporated into insulated glass units and like applications while avoiding the installation and appearance problems described above. There exists a need for such a glass sheet which serves to simulate the muntins of a traditional pane glass window. There exists a need for a glass sheet of this type which does not unduly compromise the insulating ability of the insulated glass unit. There exists a need for such a glass panel which may be cost effectively manufactured. Moreover, there exists a need for a technique and tool for forming such a decorative glass sheet.